Wrist (carpal tunnel view)
Updates to Article Attributes
The carpal tunnel view is an axial projection to demonstrate the medial and lateral prominences and the concavity 1.
It can be utilised to investigate potential hook of hamate, pisiform and trapezium factures 2.
Patient position
- patient stands with the back facing the table
- palmar surface of hand is placed in contact with the cassette which is placed at the table margin
- wrist is dorsiflexed approximately 135 degrees, making the carpals and metacarpals lift away from the cassette
X-ray beam featuresTechnical factors
-
vertical beamaxial projection -
centring point
- mid carpal region
-
the central ray is
employed -
vertical and will be centred to
an approximatethe midpoint of the dorsiflexed wrist
-
collimation
- laterally to the skin margins
- dorsal to the skin margins
- ventral to the carpometacarpal joint
-
orientation
- portrait
-
detector size
- 18 cm x 24 cm
-
exposure
- 50-60 kVp
- 3-5 mAs
-
SID
- 100 cm
-
grid
- no
Image technical evaluation
There should be a clear outline of the ventral aspect of the carpal bones with no superimposition.
Practical points
This is a very specialised and slightly outdated projection, yet it is still important to know how to perform it, especially if you don't have a CT scanner readily available.
You can also achieve this projection sitting down, with the hand in forced dorsiflexion; It is often best to ask the patient to pull their fingers back to achieve adequate dorsiflexion, after of course showing them how this is performed. You can then aim the central straight down the carpal tunnel region.
Just remember this an cause the significant patient pain if not performed correctly, It is best to demonstrate to the patient physically what you plan to do before making them perform it, this way they are not in discomfort for long.
-<p>The <strong>carpal tunnel view</strong> is an axial projection to demonstrate the medial and lateral prominences and the concavity <sup>1</sup>.</p><h4>Patient position</h4><ul>-<li>patient stands with back facing the table</li>- +<p>The <strong>carpal tunnel view</strong> is an axial projection to demonstrate the medial and lateral prominences and the concavity <sup>1</sup>.</p><p>It can be utilised to investigate potential hook of hamate, pisiform and trapezium factures <sup>2</sup>.</p><h4>Patient position</h4><ul>
- +<li>patient stands with the back facing the table</li>
-</ul><h4>X-ray beam features</h4><ul>-<li>vertical beam is employed </li>-<li>centred to an approximate midpoint of the dorsiflexed wrist</li>-</ul>- +</ul><h4>Technical factors</h4><ul>
- +<li><strong>axial projection</strong></li>
- +<li>
- +<strong>centring point</strong><ul>
- +<li>mid carpal region</li>
- +<li>the central ray is vertical and will be centred to the midpoint of the dorsiflexed wrist </li>
- +</ul>
- +</li>
- +<li>
- +<strong>collimation</strong><ul>
- +<li>laterally to the skin margins</li>
- +<li>dorsal to the skin margins </li>
- +<li>ventral to the carpometacarpal joint </li>
- +</ul>
- +</li>
- +<li>
- +<strong>orientation </strong><em> </em><ul><li>portrait</li></ul>
- +</li>
- +<li>
- +<strong>detector size</strong><ul><li>18 cm x 24 cm</li></ul>
- +</li>
- +<li>
- +<strong>exposure</strong><ul>
- +<li>50-60 kVp</li>
- +<li>3-5 mAs</li>
- +</ul>
- +</li>
- +<li>
- +<strong>SID</strong><ul><li>100 cm</li></ul>
- +</li>
- +<li>
- +<strong>grid</strong><ul><li>no</li></ul>
- +</li>
- +</ul><h4>Image technical evaluation</h4><p>There should be a clear outline of the ventral aspect of the carpal bones with no superimposition.</p><h4>Practical points</h4><p>This is a very specialised and slightly outdated projection, yet it is still important to know how to perform it, especially if you don't have a CT scanner readily available. </p><p>You can also achieve this projection sitting down, with the hand in forced dorsiflexion; It is often best to ask the patient to pull their fingers back to achieve adequate dorsiflexion, after of course showing them how this is performed. You can then aim the central straight down the carpal tunnel region. </p><p>Just remember this an cause the significant patient pain if not performed correctly, It is best to demonstrate to the patient physically what you plan to do before making them perform it, this way they are not in discomfort for long.</p>
References changed:
- 2. Abbitt PL, Riddervold HO. The carpal tunnel view: helpful adjuvant for unrecognized fractures of the carpus. Skeletal radiology. 16 (1): 45-7. <a href="https://www.ncbi.nlm.nih.gov/pubmed/3823960">Pubmed</a> <span class="ref_v4"></span>